What is the order of transformations when exporting to Collada?
Object and bone transformation in Blender are applied in the order of scale, rotation, translation. As a matrix this would be written like this:

object_matrix = translation_matrix * rotation_matrix * scale_matrix


Note that this order ensures there is no shearing, which happens when you do scaling after rotation.

If parenting is included in the matrix, multiple such object or bone matrices might be multiplied together, which means there is no longer a clear correct way to decompose the matrix into scale, rotation and translation.